Functional respiratory imaging to predict post-operative forced expiratory

Current ACCP guidelines (Colice et al., Chest 2007) recommend usage of the segment count method and the perfusion scintigraphy method for calculating post-operative forced expiratory volume in 1 second (FEV1) in patients undergoing a lobectomy or pneumonectomy, respectively. In this trial, functional respiratory imaging (FRI) (De Backer et al., Radiology 2010) is evaluated for calculating post-operative FEV1 (poFEV1). Methods 23 patients (14 analyzed [10 single lobectomy, 2 double lobectomy, 2 pneumonectomy], 9 dropouts [2 deceased, 3 lost in follow up, 4 sub-lobar resection]) were included in the trial. All patients underwent spirometry, perfusion scanning, and pneumotach controlled CT scanning at maximum expiration (RV) and inspiration (TLC), both before and after resection. Post-surgery tests were acquired after recovery and before the start of any adjuvant therapy. RV and TLC scans were used to segment lobar volumes and to calculate regional expansion (EXP). Furthermore, resistances (iRaw, before and after virtual resection) were acquired through computational fluid dynamics. poFEV1 was predicted using the guideline formulas and using the FRI based formula (Figure 1). Results Median actual poFEV1 is 2100 ml (1210 ml -- 3210 ml). The slopes of the fitted linear models between the actual and predicted poFEV1 are 1.10 (R2=0.81, p<0.001*) and 0.98 (R2=0.86, p